Modeling the Antibody-Parasite Interaction During Chagasic Infection with Two Different Parasite Lineages

S. VEGA; G.J. SIBONA; C.A. CONDAT; S. COSSY ISASI

Los Cocos, Córdoba

Congreso; XXXVIII Reunión Anual de la Sociedad Argentina de Biofísica; 2009

Sociedad Argentina de Biofísica

Starting with our previously developed model for the parasite-antibody interaction during Chagas disease, we studied the different outcomes of the acute phase of the infection when it is caused by parasites belong to two different lineages. Clinically, it is observed that there are two major phylogenetic lineages, T. cruzi I and T. cruzi II, typically associated with sylvatic and domestic cycles, respectively. Our model predicts the existence of three possible steady states: a) Healing, with the complete elimination of both parasites types, and b) and c) Chronic states, where one parasite lineage reaches an equilibrium with the immune system, while the other is eliminated. No stable coexistence of both lineages is predicted. This result, combined with the different characteristics of each lineage, could be the explanation for the prevalence of one lineage during sylvatic transmission and of the other during domestic transmission. We also show phase diagrams and portraits of the joint infection for different types of parasites.